A condition in which blood vessels within the placenta or the umbilical cord are trapped between the fetus and the opening to the birth canal, a situation that carries a high risk the fetus may die from hemorrhage due to a blood vessel tearing at the time the fetal membranes rupture or during labor and delivery. Another danger is lack of oxygen to the fetus.
Vasa previa often occurs with a low-lying placenta (due to scarring of the uterus by a previous miscarriage or a D&C), an unusually formed placenta (a bilobed placenta or succenturiate-lobed placenta), an in-vitro fertilization pregnancy, and multiple pregnancies (twins, triplets, etc). Vasa previa also may accompany velamentous insertion of the umbilical cord.
Vasa previa may not be suspected until the fetal vessel rupture occurs. Reduction in fetal mortality depends on prenatal diagnosis. When vasa previa is found before labor, the baby has a much greater chance of surviving. Vasa previa can be detected during pregnancy as early as the 16th week of pregnancy with use of transvaginal sonography in combination with color Doppler.
When vasa previa is diagnosed, C-section before labor begins can save the baby’s life. The C-section should be done early enough to avoid an emergency, but late enough to avoid problems associated with prematurity.
Relating to blood vessels. For example, the vascular system in the body includes all of the veins and arteries. And, a vascular surgeon is an expert at evaluating and treating problems of the veins and arteries.
- Vascular bed
The vascular system, or a part thereof. For example, the pulmonary vascular bed describes the blood vessels of the lungs.
- Vascular dementia
A common form of dementia in older persons that is due to cerebrovascular disease, usually with stepwise deterioration from a series of small strokes and a patchy distribution of neurologic deficits affecting some functions and not others. Symptoms include confusion, problems with recent memory, wandering or getting lost in familiar places, loss of bladder or […]
- Vascular endothelial growth factor (VEGF)
A substance made by cells that stimulates new blood vessel formation, a mitogen for vascular endothelial (vessel lining) cells. VEGF is a polypeptide structurally related to platelet-derived growth factor (PDGF). The gene for VEGF is on chromosome 6p12.
- Vascular headache
A group of headaches felt to involve abnormal sensitivity of the blood vessels (arteries) in the brain to various triggers which results in rapid changes in the artery size due to spasm (constriction). Other arteries in the brain and scalp then open (dilate), and throbbing pain is perceived in the head. Migraine headaches are the […]